There is a plurality of applications where rotational movement has to be converted to another different movement type. For instance, in machines like eccentric press, crank-connection rod mechanisms are used converting rotational movement to linear movement. In more details, such presses operate with the kinetic power of a big circular metal (flywheel) accelerated by an electric motor. Accordingly, the flywheel rotates continuously by means of the rotation movement it takes from the motor, however, the flywheel spindle does not rotate. When it is desired to be pressed on the piece, the flywheel spindle begins rotating by means of a clutch control like pedal. The rotation movement on the flywheel spindle is transferred to the eccentric spindle functioning as a crank by decreasing of the rotation number by means of gears. The function of the eccentric spindle is to transform circular movement to linear movement. Thus, linear movement (it is called press movement distance or stroke in the related technical field) equal to the eccentricity of the crank spindle is realized to the movable ram connected to the rod arm which is connected to the press crank spindle.
This embodiment which is widespread in the technical field has some disadvantages. For instance, in general the movement distance (it is called course in the related technical field) in these presses is constant. On the other hand, in press processes, the movement distance of the manufactured piece required with respect to the drawing depth changes. Therefore, in crank-connection rod and link-drive mechanism presses, the press is designed with respect to the maximum movement distance required and it realizes said course in every tour thereof even if most of the time this is not required. This means making the upper mould and the ram body do unnecessary movements and lose energy.
In the presses (course adjusted presses) where the movement distance can be adjusted, this adjustment process is a process which takes a long time and which requires labor. The amount of the eccentricity is determined using a piece called wedge for adjustment whose thickness increases along the length thereof, thus the press movement distance is increased or decreased. For this process, naturally the press should be stopped for a while and thus the production in the line where the press is placed should be stopped for a while. This process which takes a long time to be completed leads to time and production loss in mass production lines. Moreover, in the presses with low tonnage and in C-type presses, automatic course adjustment can be realized.
Moreover, as known in the technical field, in order to obtain a functional movement characteristic, the displacement distance should be limited in maximum to the radius of the eccentric gear. Thus, for longer distances, eccentric gears with a bigger diameter should be manufactured. This situation limits the movement distance of the press to be produced, with the bench capacity used in thread forming; thus since a more advanced technology is required for processing bigger gears than a certain size, this increases costs seriously.
Another problem is that in these types of presses, particular movement characteristics can not be realized. For instance, in a press application, the press may have to move downwardly with a slow movement, it may have to accelerate after a certain point and it may have to stay for a certain time in press position to the piece. As a result, such a movement characteristics can not be realized by a standard crank-connection rod mechanism. Such an operation can be realized only by expensive systems like servo press in the present art.
As an advantageous and different solution, some press embodiments using a gear box similar to a planet gear system as drive transfer mechanism are disclosed. As known, planet gear system in general decreases revolution as a gear box, or it can be used for increasing torque or for decreasing torque. Accordingly, the concentricity of the ring gear, the planet carrier and the sun gear provides an important advantage in the fields requiring concentric power transfer. The planet gear systems which are the subject of these patents realize the transformation of rotational movement to linear movement, therefore they are used for a different purpose.
For instance, in the U.S. Pat. No. 3,158,057 where the drive system of a cinnamon cutter blade is explained, a main planet gear whereon a rod arm is hinged is moved along the inner surface of a main planet gear ring gear in a circular route and thus the rod arm moves downwardly-upwardly in a linear direction. In this embodiment, since the other planets and the sun gear are removed from the mechanism, the mechanism disclosed can not be used in processes with high tonnage where high response forces are formed. In practice, since all of the load will be applied to the hinge point on the main planet gear of the rod arm, the connection here can not endure the forces of hundreds and even thousands of tones. Anyhow since the mechanism in U.S. Pat. No. 3,158,057 is used for cinnamon cutting process, in such a process, high response forces do not exist, thus U.S. Pat. No. 3,158,057 does not comprise a solution in this direction.
In the U.S. Pat. No. 2,338,352, a press embodiment is disclosed which is suggested to endure high level of forces and which has a drive transfer mechanism similar to planet gear. Accordingly, an inner gear whereon the rod arm is hinged eccentrically realizes both rotational and orbital movement along the inner surface of a circular gear, thus the elliptical movement formed is transferred to the rod arm as a linear movement. However, in this patent, an effective solution which will distribute the force arriving to the main planet gear where the rod arm is hinged is not disclosed.
As a result, because of the abovementioned disadvantages, a novelty is required in the related technical field.